Method of transforming electrical energy.



E. WBINTRAUB. METHOD or TRANSFORMING' ELECTRIGAL ENERGY.

APPLICATION FILED FEB. 26, 1902.

1,086,102. Patented Feb. 3, 914.,

Wnmassas INVEHTOR ligechiel Wein+mub UNITED STATES PATENT OFFICE.

EZECHIEL WEINTRAUB, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERALELECTRIC COMPANY, A CORPORATION OF NEW YORK.

METHOD OF TRANSFORMING ELECTRICAL ENERGY.

Specification of Letters Patent.

Patented Feb. 3, 1914.

Application filed February 26, 1902. Serial No. 95,661.

To all whom it may concern Be it known that I, EZECHIEL Wam- TRAUB, asubject of the Czar of Russia, residing at Schenectady, county ofSchenectady, State of New York, have invented certain new and'usefulImprovementsin Methods of Transforming Electrical Energy, of which thefollowing is a specification.

The invention hereinafter described and claimed relates broadly to thetransformation of electrical energy, and more especially to ,theproduct-ion of light through the medium of vaporous or gaseous mattermain-- tained in a luminescent condition by electric energy. In lampswherewith I practise my invention perhaps the most generally useful andconvenient material to employ is the vapor of mercury and it is of thisvapor that I chiefly make, use, though it is of course to be understoodthat I do not wish my invention to be limited to the employment of thisvapor only.

In lamps of the character described, various difiiculties anddisadvantages are attendant upon the means heretofore employed forstarting the arc. The usual method of startlng, of which of course thereare various modifications, is to impress upon the electrodes of thelamp, for a certain period or periods, a high electro-motive force, manytimes greater in value than the normal electro-motive force at which thelamp is intended to operate. This starting electromotive force operatesor at least. appears to operate to break down the high initialresistance or opposition to current flow between the electrodes of thelamp whereupon the lamp starts.

My present invention, among other valuable features, provides a meanswhereby the arc, in a lamp of the type mentioned, may be started intooperation by the utilization of moderate electro-motive forces, such forexample as those normally employed by the lamp. though my invent-ionpermits a wide range of starting electro-motive force.

Before passing on to the explanation of my invention in detail it mayperhaps be I well to state first certain considerations the are byprojecting into its ofmercury or other similar vapor.

which may aid in explaining the theory of operation-of the lamp.In'general, I start path the vapor It is not suflicient that this vaporshould be of that form which would be produced by the.

evaporation of mercury by heat, for when in this'condition it has beenfound that the mercury vapor is practically, or at least nearly, anon-conductor for the electric current, so that the presence of suchvapor not only does not help the lamp to start, but actually hinders it.Something more is neces'. sary and this necessity requires that themercury should be not only in the form of a vapor but this vapor shouldbe in an ionized condition. It is perhaps impossible to state exactlyWhat this condition is but it will be sufficient for the present purposeto state that when in the ionized condition the mercury vapor is a goodconductor of the electric current, whereas ordinary mercury vapor ispractically a non-conductor. I have found that such ionized mercuryvapor may be produced within the inclosing or containing member of thelamp by means of a supplemental or auxiliary mechanism operating atcomparatively low electro-motive force and that this ionized vapor onceproduced immediately causes current to pass between the main electrodesof the lamp, which thereupon operates normally. The lighting up of themain tube, so far as the eye cansee, is or may be simultaneous with theinitiatory production of the ionized vapor by the supplemental orauxiliary device.

After the lamp has been started, the supplemental or auxiliary mechanismor means for generating the ionized vapor may be cut out of circuit orotherwise put out of.

action if desired, and this operation may be performed either manuallyor automatically. I have found however that if this auxiliary orsupplemental source of ionized vapor be continued in operation a mostimportant advantage may be secured. When the lamp is maintained incircuit under certain conditions either of impressed voltage or ofcurrent supply, it may become unstable in action. This may happen forexample when the lamp is made to run with reduced current, in which caseit may frequently flicker or go out entirely. If, however. the auxiliaryor supplemental source of ionized vapor be maintained in action. thisinstability disappears and the lamp will be steady and stable inoperation throughout extremely wide variations in impressed voltage orcurrent supply. I account for this on the theory that any tendency ofthe lamp to go out, or any tendency to undue reduction of current, isinstantly counteracted by the supply of ions produced by the supplemental source, these ions immediately bringing back'the flow of currentto its normal value.

My invention further comprises various features for assisting thebeneficial effects of the starting means, particularly useful inrelatively long lamps. In carrying out this last feature of my inventionI provide one of the electrodes of the lamp with a conducting mediumextending in the direction of the other electrode. This conductingmedium may be in the form of a carbon filament, though in thisconnection I may employ a filament, rod, or other suitably shapedconductor of carborundum or of graphite or of mixtures of carborundum,graphite and clay since these materials possess the valuable advantagethat they do not occlude gases to any extent nor do they, by the actionof heat, become chemically changed in such a manner as to produce gases.This advantage is extremely important since, in

lamps to which my invention is to be applied, it seems to be necessarythat the vacuum or degree of exhaustion should be as near absoluteperfection as possible. Thus,

I get good results in long tubes with a vacuum represented by 1/1000 ofa millimeter of mercury.

My invention comprises also other valuable features together withvarious details of construction and arrangement, all of which will beset forth more specifically in the following description, taken inconnection with the accompanying drawings, in which Figure 1 representsone embodiment of my invention, and Fig. 2 an arrangement containingcertain additional features.

In Fig. 1 a lamp is shown, the main body portion of which consists of astraight tube 1 of somewhat indefinite length as indicatedconventionally by the dotted lines 2, 2. The length of the tube variesin accordance with the voltage in connection with which the tube is tobe used. The lower end of the lamp contains a body of mercury 3extending down into a contracted neck 4 of the tube, with the lower endof which communicates a terminal 5 which may be of platinum or othersuitable material having the proper coeflicient of expansion. The bodyof mercury 3 above referred to, constitutes one of theoperativeelectrodes of the lamp and is connected with the negative conductorleading from a source of direct current, whereby it acts as a cathode.At the opposite end of the tube is the anode 6. This may be formed ofvarious materials such as iron, silicon, carborundum, or mixtures ofcarborundum, graphite and clay, carbon, graphite or..a mixture ofgraphite and clay. Graphite, carborundum and clay possess the advantagethat they do not tenaciously retain occluded gase nor do they, whenacted upon by heat, undergo such chemical change as would give rise tothe production of gases, the advantage of which is set forth above. Theelectrode 6, to which reference has been made, is connected by aplatinum or other suitable wire 7 passing through a glass wall into anexhausted chamher 8 through which, by means of a coiled or extensiblewire 9, connection is made with the exterior terminal 10 of the lampwhich terminal is connected to the other pole of the source of directcurrent. The object of the supplemental exhausted chamber 8 is torelieve the pressure around the joint between the platinum wire 7 andthe glass surrounding it, thereby reducing, as far as possible, anytendency toward leakage of air into the main tube. In connection withthe main lamp electrodes thus described, there will be noticed anadditional or supplemental elect-rode, consisting in this instance of abody of mercury 11, normally separated from the mercury 3 but inproximity thereto, and contained within a cavity 12 from which depends atubular extension 13 into which projects one end of a supplementaryexterior terminal 14 sealed through the glass forming the walls of theextension.

I find it extremely desirable, if not absolutely necessary, that themercury should be introduced into the tube in as pure a condition aspossible, and I find that this may be done by placing the mercury firstwithin a vessel, not shown, communicating with the main tube 1 through asuitable passage as, for example, through the tubular extension 24, andthen distilling the mercury into the main tube in vacuum. The extensionmay then be sealed ofl as shown. After the mercury has been introducedinto the tube, the latter must be evacuated to as high a degree aspossible, which is done by pumping, through the extension 15, and thispumping must be continued for a greater or less length of time after thelamp has been put into operation in order to withdraw all occluded orother gases which may be set free in the tube during the initialoperation of the lamp. When gases are no longer given off, and thevacuum shows no signs of impairment, the connection between the tube andthe pump may be sealed off.

In order to start the lamp on an ordinary direct current circuit, themain terminals 5, 10, are connected with a source of current in such amanner that the mercury electrode 3 shall be the cathode and theelectrode 6 the anode. The supplemental electrode 11 is also connectedto this source of current so as to form a supplemental anode.Resistances 16 and 17 may be connected respectively in series with themain and supplemental anodes to adjust the current flow.

These resistances also have a steadyin effect. The terminals of the lamphaving en connected as described, the lamp may be started into operationby gently shaking the lower end of the lamp, which may be supported fromits upper end by the ring 18 or some other suitable'arrangement. Thisact of shaking,-which in some instances may amount to no more than adelicate touching of the lamp, causes mercury to flow so as momentarilyto connect the two electrodes 3 and 11, and, upon their disconnection,as the mercury recedes, gives rise to an are or discharge between thetwo bodies of mercury. The accompanying liberation of ions by theelectrical vaporization of the mercury instantly causes current to flowbetween the main electrodes 3 and 6 of the lamp, which is thereuponfilled with a brilliant whitish light. My present belief is that theaction is a projection of ions which extends from the cathode toward orto the anode, and forms a conducting path and ultimately an arc, thusenabling the normal voltage of the lamp to initiate the flow of currentbetween the main electrodes when such voltage, unassisted, would beincapable of doing so. It is certain that the initial opposition to theflow of the main current in the tube, if such a word as opposition maybe used, is very considerable and has heretofore required theapplication of an electro-motive force of many hundreds of volts to themain electrodes of the tube in order so far to break down this initialopposition as to allow a moderate service electromotive force of theorder, say of 100 volts, to set up and maintain the normal flow ofcurrent in the tube. Electrically vaporizing mercury within the v tube(va orization merely by heating would be ine ective because the vaporthus produced is non-conducting), or otherwise liberating free ions atthe surface, gives rise to a conducting vapor which may be distinguishedfrom the ordinary vapor of mercury by designating it as ionized vapor.This ionized vapor, being produced locally, spreads out through thetube, as I believe by a propulsion of its charged molecules along thestatic lines of force in the tube. The ions thus liberated by thevaporization of mercury at the surface of the main cathode 3 aretherefore conveyed toward the main anode 6 and the whole time flashesinto brilliance, the migration of ions from the main cathode usuallyreaching its normal rate instantaneously after the action has once beenstarted up through the operation of the supplemental or auxiliary anodein the manner described.

It will be seen that while prior inventors have concentrated theirefforts on devising means for conveniently generating electromotiveforces high enough to forcibly break down from without the initialopposition of the tube, my invention, in the aspect I am now discussing,regardless of theory or nomenclature, is characterized by thefundamental distinction that I first weaken and, as it were, underminethis opposition to the flow of current so that I am then able toovercome it by service electro-motive forces if desired. The simplestway of practising my invention in its broadest aspect is to impress uponthe main electrode of a tube in which the auxiliary electrode is eitherabsent or inoperative a moderate electro-motive force, and then to shakethe tube so as more or less violently to agitate or break up the surfaceof the mercury terminal, whereupon the opposition to flow of currentwill be so far reduced as to enable the electro-motive force impressedupon the terminals to start the lamp into operation.

In order to assist the flow of current between the main electrodes of alamp of the character described, I have discovered that it is veryadvantageous to bring one of the electrodes, as for example the anode,within electrical proximity so to speak of the other electrode, and thismay be done by extending from the anode a suitable electrical conductorsuch for example as a carbon filament or rod or a filament or rod formedof graphite or carborundum or of mixtures of these substances and clay,this rod having one end electrically connected to the anode and theother end extending toward the cathode but not into contact therewith.This rod it may be found necessary in many instances to support in acentral position by means of a suitable anchoring device or devices.Such a structure I have represented in 'Fig. 2 in a lamp shown withoutits electrical connections. This lamp is similar in most respects tothat shown in Fig. 1 but contains in addition the anode extension 19 inthe form of a small filament of'material such as described. Thisfilament is anchored by means of a ring or hook 20 supported by a hollowpiece of glass 21 sealed through the wall of the main tube. This hollowglass body has a small opening 22 between the interior thereof and thetube, whereby when the main tube is exhausted the interior of the bodymay likewise be exhausted, thereby doing away with any danger to thevacuum of the tube should any accident such as cracking or the likeoccur to the glass body supporting the anchoring ring or hook 20. Whenthe auxiliary arcing or starting device is put into operation, theconducting vapor proceeding from the main cathode 23 of the lamp seems,by the presence of the filament or rod 19, to be able more readily toreach the main anode than when no such rod or filament is used, theaction being one in which the vapor, by reaching the projecting endsof'the filament, flows along quality until it reaches the anode. Thisex-' tension of one of the lamp electrodes toward the other by anelectric conducting medium is particularly useful in connection withrelatively long tubes. I

I have set forth above that the auxiliary arc may be started by a manualagitation of the lower end of the tube which may, if desiredfbe providedwith a knob 24.- to*serve as a hold for the fingers. Instead, however,of manual operation, I may employ electrical or electro-mechanicalmeans, and such means I have disclosed and claimed in ap; plicationsfiled concurrently herewith.

The supplemental or auxiliary anode, by the cooperation of which withthe main cathode the secondary or starting arc is produced, may ifdesired be cut out of circuit after the lamp starts into operation, andfor this purpose suitable automatic devices may be used, such as I havedisclosed and claimed in other applications filed concurrently herewith.If, however, the supplementary or secondary are be maintained duringnormal operation of the tube, I find that there results the importantadvantage that in case the lamp for any reason has any tendency towardunstable operation, this is entirely prevented. Furthermore where themain arc alone would be stable within a very narrow range of current,the range of stability is materially increased by the presence of thesecondary arc, making it possible to vary the main current. of the tubefrom a small minimum value up to the point where the current is. sogreat as to destroy the tube. By the use of an adjustable seriesresistance, the lamp may, so to speak, be turned up or down, or, inother words, its luminoslty increased ordiminished without departingfrom a condition, Since the lamp con-' of stable operation. sumesasubstantially constant voltage at its terminals at all currents, andsince I have found by experiment that the ratio of the light to theenergy consumed in the tube itself is within wide limits substantiallyindependent of the current density, the efliciency of the lamp underthese different conditions remains practically constant. Thus if theresistance in series with the lamp is doubled, the current ispractically halved, the drop of potential across the resistanceremaining practically the same as before,

and the efiiciency of the lamp the same as before or substantially soWhat'I claim as new and desire to secure by Letters Patent of the UnitedStates, is,

1. The method of starting an arc by applying an electromotive force tothe electrodes between which the arc is to exist,

and then agitating one of the electrodes, which electrode is of a mobilecharacter, so as to permit an ionic discharge to flow under theinfluence of the electromotive force mentioned.

2. The method of starting an are, which consists in applyin anelectromotive force suitable for norma' o eration to the electrodesbetween which t e are is to exist, one of which electrodes is liquid,and then so agitating the liquid as to permit an ionic discharge toflow. under the influence of electromotive force mentioned.

3. The method of starting an are, which consists in applying anelectr'o-motive force to the electrodes between which the arc is toexist, one of which electrodes is vaporizable, and then independentlyagitating the vaporizable electrode so as to cause an ionic discharge toflow under the influence of potential difference due to theelectromotive force mentioned. a

4. The method of securing stable operation of an electric lamp of thattype in which a vapor is maintained by the electric current in aluminescent condition, which of the main current of the lamp, whichconsists in supplementing said vapor by vapor produced by a stablesource.

6. The method of securin a steady flow of current between electro esthrough a body of vapor, which consists in compensating for any tendencytoward variation of resistance of said body ofvapor by causing asupplegnental generation of ionized vapor.

7. The method of securing stable operation of an arc from an electrodevaporizing at low temperature, which consists in maintaining a shorterauxiliary or steadying are springing from the same electrode.

8. The method of producing and controlling light, which consists indrawing an are from a main electrode, drawing a supplementa or steadyingare from the said electro c and varying the opposition to current flowin the main arc.

In witness whereof I have hereunto set my hand this 24th day ofFebruary, 1902.

EZECHIEL WEINTRAUB.

Witnesses:

ALEX. F. MACDONALD, Hnmm Onronn.

